Focus

Cubic isotropic MgAl2O4 spinel can be regarded as an almost ideal transparent ceramic material.
It is an attractive material in the aerospace sector for several applications under severe conditions such as hard front layer in transparent protection and rugged optical windows operating in harsh environment.
CNR ISTEC optimized the production process of spinel components with an in-line transmittance up to 82 % close to the theoretical value

Hydroxyapatite (HA: Ca10(PO4)6(OH)2) is a widely used biomaterial for the repair and regeneration of bone defects; however HA is also recognized as a very interesting material for environmental purification due to its ability to easily absorb a number of inorganic compounds as well as different organic substances such as proteins and bacteria. In this respect, specific ion substitutions in the lattice of HA can enable specific functionality so to open the way to multi-functional and ...

Bioactive hydroxyapatite nano-phases endowed with intrinsic superparamagnetism, designed to act as new stimuli-responsive drug delivery systems or to enhance cell homing and colonization of bone and osteochondral scaffolds thus enhancing tissue regeneration.
The recent development of new intrinsically superparamagnetic hydroxyapatite nanoparticles (Fe-HA) was achieved through controlled substitution of Ca2+ ions with Fe2+/3+ ions, with specific Fe/Ca and Fe2+/Fe3+ ratios. Due to the bioactivity, ...

3D hybrid biomimetic and bio-resorbable scaffolds for the complete regeneration of multi-functional regions like osteochondral and periodontal sites are developed by a well-established bio-inspired synthesis mimicking the biologic neo-ossiﬁcation process, thus providing the new devices with very high regenerative ability. The scaffolds are based on Type I collagen fibers that assemble, organize and mineralize with biomimetic, ion-substituted hydroxyapatite nano-nuclei upon pH variation at ...

Hybrid porous nano-composites to be used as filtering devices and moisture exchange systems are developed with complex geometry contributing to the water and nano-particles trapping (including the unrestrainable particle with dimensions in the range of 30-100 nm) without excessive pressure drop.
The hybrid composites are developed through a biomineralization process induced starting from a suspension of blended natural polymers (e.g. gelatine, chitosan, alginate) in the presence of Ca2+ and ...

Polycrystalline YAG (Y3Al5O12) doped with rare earth elements (REE) is a strategic functional material as laser source for high power Diode Pumped Solid State Lasers(DPSSL).
Compared to the more commonly used single crystals, transparent YAG ceramic can widen the laser applications:
It can be highly doped
It is faster to produce
It can be shaped in complex architectures.

The experience gained in the field of colloidal science has been fruitfully transferred to the control of nano particles (NPs) confinement and surface chemistry, opening new challenges towards the control of potentially adverse health impact of nanomaterials.
EXPECTED IMPACTS _ Some of the very high impacts expected by the present research are:
o The development of practical and cost effective strategies for reduction of worker exposure to NMs during all stages of NMs production, use and ...

The development of hydraulic mortars by using as binder slaked lime, historic material, and natural hydraulic lime, that, at the present time, is the most lime typology used in the restoration and building fields. Metakaolin is obtained by calcinating at 650°C a commercial kaolin and it is used as pozzolanic admixture.
Our study is focalised on the realisation of: 1) injection mortars for consolidation or re-adhesion systems previously disconnected or detached; 2)structural mortars that ...

In the restoration works, the use of products compatible with the materials composing the heritage artworks is important. The majority of materials of Cultural heritage (ceramics, mosaics, mortars, stones) is made of natural inorganic raw materials, so it is crucial in the conservative intervention to use inorganic non-metallic compounds, that in some cases are the same components of the cultural heritage. For this reasons, we are setting up products gotten by modification of inorganic raw ...

SOEC are produced at ISTEC starting from powders obtained by conventional solid state synthesis or chemical routes (precipitation, sol-gel, etc.). The powders are synthesized with characteristics suitable for the subsequent shaping processes. The cell fabrication consists in depositing the cell elements onto a supporting-element produced by tape casting. All the possible substrates for SOEC were produced with this technique:
anodes: La0.6Sr0.4Fe0.8Co0.2O3 (LSCF), La0.8Sr0.2MnO3 (LSM);
...

Joining techniques permit to build complex and potentially multimaterial structures that cannot be obtained directly with the densification process.
Bonding is necessary to fully exploit the potential of several hi-tech ceramics.

Gas separation membranes are electrochemical devices that allows the separation of specific components contained in gas streams at high temperatures (500-800°C). These systems can be classified on the bases of the materials used as :
Oxygen separation membranes;
Hydrogen separation membranes.
These devices are ceramics or ceramic-metallic bilayers constituted of a supporting element and an active layer. Separation membranes are produced at ISTEC starting from commercial or synthesized ...

Dye Sensitized solar cells, also known as Grätzel cells, are devices used to directly convert solar light into electricity. In 1991 O'Regan and Grätzel realized the first prototype of solar cell with good efficiency using low-cost materials if compared to silicon solar cell.
DSSC (Dye Sensitized Solar Cell) are made of multilayer materials with selected band gap that allow photon adsorption and electron injection in the conduction band of the anodic material to produce electric energy. Heart ...

The regeneration of hard connective tissues (e.g. bone, teeth) is activated by the presence of specific chemical and morphological signals inducing new bone formation and organization. In this respect hydroxyapatite phases presenting bone-like composition (i.e. multiple ionic substitutions such as Mg2+, CO32-, Na+, K+, SiO44-, Sr2+), nanosized microstructure and low crystal order can be synthesized by wet methods at room temperature. These new phases closely mimic the inorganic part of bone and ...

The ultra-high temperature ceramics (UHTCs) draw the interest of the materials engineering to designe thermal protection structures and control surfaces for the sharp leading edge technology. Sharp leading edges for reentry vehicles or hypersonic space-crafts are two leading examples. Thhank to this new concept, improved flight performances together with enhanced safety for the crew, larger cross-range, wider launch windows, and safer landing for aborted flight plans can be achieved.
Ceramic ...

A heat pipe is a heat transfer device that can exchange large quantities of heat with a very small difference in temperature between the hot and cold interfaces by means of evaporation and condensation of a working fluid. The evaporator is the heart of the device and it contains capillary-porous structures generally based on metals or organic polymers. A possibility to increase the capacity of thermal exchange is through the replacement of conventional materials with ceramic like materials such ...

The regeneration of critical-size bone defects requires the implantation of porous scaffolds exchanging suitable chemical, morphological and mechanical signals with cells so as to activate new bone formation and colonization of the whole scaffold. Pore size and morphology must be designed to achieve cell penetration and the establishment of a suitable vascular network to sustain the bone metabolism. The mechanical strength of the scaffolds should be sufficient for early physical stabilization ...

The introduction of inorganic natural or artificial pigments permit to obtain colored geopolymers can be used in the restoartion field. The mechanical and physical characteristics are able to use the obtained products for realising musive tesserae. At the present, briquettes of different colors are realised. the obtained tesseare can also be used to realise modern mosaics as altenartive solutions to resin tesserae.

To mitigate the impact of fossil energy on pollution and greenhouse effect, the current technologies need to be improved for achieving limited environmental impact and high sustainability (zero emission). When CO2 sorbents are used in granular or structured forms, high superficial area and well developed open porosity are prerequisites for an effective process. A typical continuous process also requires the sorbent to be mechanically resistant, regenerable and easily available. ISTEC has tested ...

Wool-geopolymer composite pots were produced as an alternative to commonly used peat ones. Already grown plants and seeds were studied over a period of 6 weeks. First results outlined that wool-geopolymer pots promote the earlier growth of seeds comparing to the reference ones. The alkaline environment of the geopolymer is indeed able to partially degrade the keratin structure of the wool (but preserving the fibers' nature), making most nutrients readily available for the sprouts. Moreover, the ...

Besides the process technologies used, the successful production of high efficient ceramics is strictly related to the chemical-physical characteristics of the starting powders. For this objective, ISTEC has implemented conventional synthesis method applying innovative heating systems (i.e. microwaves, infrared) for the production of ceria-based powders with high chemical-physical reactivity and high purity and morphological control (in Figure). These systems have been exploited for catalytic ...

ZEBRA batteries (Zero Emission Battery Research Activities), due to their high energy and power density, are one of the best solutions to the actual energy storage demand for stationary application and to the sustainable mobility with electric and hybrid cars.
These systems are based on nickel-sodium chloride cells operating at high temperatures (about 270°C-350 °C), enclosed in a thermal container and uses a ceramic tube or planar membrane of Na-β"-alumina as solid electrolyte.
The ...

New generation thrusters demand always increasing severe combustion conditions, in terms of temperature and pressure, in order to enhance their performances.
Materials based on carbides of the early transition metals, such as zirconium, hafnium and tantalum, are promising systems for these applications, combining physical properties of ceramics and electronic properties of metals: high melting points (> 3900°C), high hardness and modulus, high thermal conductivity especially at elevated ...

ISTEC activities mainly deal with the study and optimization of those ceramic processes cheap and easily scalable able to produce the abovementioned ceramic devices in an easy and environmental friendly way. ISTEC exploits the most common techniques used in the traditional ceramic industry:
tape casting,
die pressing,
screen printing,
powder wet spray,
to optimize the production of the three generations of planar SOFC:
electrolyte-supported cells,
electrode-supported cells,
...

The potential field of application of porous ceramics is increasing; the porosity is a functional property, so that 3D porous ceramics with interconnected and distributed open pores are designed for the specific application. Water-based freeze casting, "ice-templating", is a novel technique to fabricate porous ceramic 3D structures with main unidirectional oriented pores, a high open porosity and the final components resulting in a lamellar or laminate-like structure. In details, the final ...

Evaluation of the biocompatibility and biofunctionality of novel biomaterials for regenerative medicine after trauma or degenerative diseases (e.g. osteoarthritis, osteoporosis). The in vitro studies investigate cytotoxicity, biocompatibility, biofunctionality, bioactivity of biological and synthetic materials. A novel research topic is dedicated to magnetic materials, using innovative magnetic nanoparticles HA-based (patented by our lab) we can magnetize cells and guide them in a specific site ...

The characterization of ceramics at nanoscale level is of fundamental importance, especially when the interfaces between two different phases play the major role in determining the efficacy of toughening mechanisms. In this framework lies the activity of microstructural characterization by transmission electron microscopy (TEM) combined with other analytical techniques, such as electron diffraction, energy dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS). The main ...

Although research has successfully produced UHTCs with flexural strength up to 1 GPa, fracture toughness and thermal shock resistance still represent major concerns for the application of these ceramics in aerospace or in highly stressed environments. To address these issues, novel processing methods have been implemented to introduce elongated reinforcements (such C or SiC fibers) into UHTC-based matrices.
Short fiber reinforced composites:
A simple technology is applied to obtain reinforced ...

The need to produce materials with more and more demanding technological performance addressed the interest of scientists towards the engineering of the synthesis of starting solid phase. For this reason, a fundamental part of the ceramic process is now reserved to the processes of powders synthesis and functionalization. A strict control of the chemical-physical evolution of forming species is been possible through the introduction of the so-called chemical routes. These chemical routes are ...

Photovoltaic solar cell are used to convert solar light into electricity. In 1991 O'Regan and Graetzel realized a prototypes solar cell with good efficiency with materials at low-cost in respect to silicon solar cell. DSSC (Dye Sensitized Solar Cell) are made of multilayer materials with selected band gap that allow photon adsorption and electron injection in the conduction band of the anodic material to produce electric energy. The Materials and process for energy applications group of ...

The transport and energy industry it is more and more in need of complex ceramic parts with high level of accuracy (blades, rotors, turbines, etc...) able to stand harsh operating conditions while retaining the shape. This can be accomplished if the ceramic bodies can be produced in an easy and economic way. Gel-casting can be a valid alternative to injection molding for the production of large, complex-shaped components requiring highly uniform properties. This highly reproducible forming ...

PVD coatings are gradually replacing the traditional methods based on electrolytic deposition. In this context an important role is represented by nanostructured coatings, in which the film is formed by a biphasic system with a microstructure designed to prevent formation, movement and growth of dislocations and microfractures. Thanks to biphasic system, formed by nanocrystals of a hard material with particles of ca.10 nm embedded in the matrix, a nanocomposite material with a hardness 4-6 times ...

Statistical methodology to extract the mechanical properties, and the relative volumetric fraction, of the constituent phases of a composite from nanoindentation data without having to image the indentation marks.

In the activities carried out in 2007 related to transparent ceramics based on YAG (EU Project Craft NOVIGLAS COOP-CT-2004-512318, Title: Innovative high power laser system based on polycrystalline Nd:YAG for marking, engraving, cutting and micro-drilling metal surfaces) the process was set up and optimized for the production of a YAG ceramic with 80% transparency, through a selected and proper choice of raw powders. The properties are comparable with the ones measured on YAG monocrystals ...

ISTEC designed and produced the material composition and coordinated the activities for the manufacture of a massive piece based on Si3N4-MoSi2 with large dimensions (520x220x150 mm). The production processes, involving mixing-granulation of powders and uniaxial hot pressing, were carried out under the guide of ISTEC. The final prototype was obtained by mechanical machining and was tested in plasma arc jets.

The recent dramatic petroleum demand and concern on its impact on air quality and global climate has resulted in a large international research and development effort on fuel cell and power generation source. Several efforts have been made to push the fuel cells commercialization towards a more efficient, easily and cost effective production cycle. ISTEC is in the forefront of ceramic processing for SOFCs being among the very few in Italy able to produce large area (10x10cm) supporting cathodes ...

Hf-borides and carbides are ultra-refractory due to their melting points above 3200°C and their excellent thermal stability. These materials are considered very promising for their use as thermal protection barriers for the space vehicle during the re-entry in the atmosphere. A new process for the production of high density borides and carbides has been set up using pressureless sintering, that allows the production of complex shapes. The tests to evaluate the behaviour of these ceramics under ...

A silica-based composition and the related slip casting process, have been optimized for the production of complex shapes components. These components are used in the production process of metallic materials with superior properties. Thanks to the optimized ceramic materials a higher process temperature is possible, and this leads to higher performances of the obtained metallic components. This research have been conducted in the frame of a contract with a private enterprise.

New synthesis methods were set up exploiting the ability of biological
systems to store and transfer informations at a molecular level. Through
this approach, biomimetic composites based on collagen and hydroxyapatite
were prepared, directly nucleating HA nanocrystals on self-assembling
collagen fibers.
The obtained composites are perfectly corresponding to the natural
mineralised tissues (bone), with the mineral phase showing needle-shaped
morphology, nanometric size and crystallites ...

Materials tailoring is dictated by the relevant development in structural ceramics of the last five years and the ever-increasing demand of high properties. This mean actions involving composition, structure and texture. In this respect, in 2002, ISTEC has carried out three distinct activities with the aim to develop innovative ceramic materials with specific and tailored properties. About composition, Ultra-High Temperature Ceramics (UHTC) have been developed, mainly based on borides and ...